JPS63238247A - Synchronous ring made of cu alloy for gearbox - Google Patents

Abstract

PURPOSE:To obtain a synchronous ring for gearbox excellent in initial conformability at a working surface and wear resistance, by constituting the above ring of a Cu alloy having a specific composition consisting of Zn, Al, Ti, Zr, Sn and Cu and also by forming a work-hardened layer of a specific layer thickness on the working surface. CONSTITUTION:The synchronous ring for gearbox is constituted of a Cu alloy which has a composition consisting of, by weight, 20-40% Zn, 2-8% Al, 0.1-3% Ti and/or Zr, 0.1-3% Sn, and the balance Cu with inevitable impurities and further containing, if necessary, 0.1-5% Mn. Then, a work-hardened layer is formed to 5-300mum average layer thickness on the required part of the working surface, against an opposite member, or the above-mentioned synchronous ring. The above work-hardened layer can be formed by shot-blasting working, sand-blasting working, etc. By this method, the synchronous ring made of Cu alloy for gearbox having high strength and high toughness, excellent in initial conformability at the above-mentioned working surface, free from the occurrence of abnormal wear, such as bright-surface wear and adhesive wear, and capable of maintaining wear resistance over a long period can be obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a synchronizing ring for a transmission made of a Cu-based alloy, which has particularly excellent initial conformability of the contact surface with a mating member and excellent wear resistance. It is something.

[Conventional technology]

Conventionally, in general, a synchronizing ring for a transmission, as illustrated in a perspective view in FIG. - The cone makes intermittent surface contact under high surface pressure, while a key groove 3 into which a key fits is formed on the outer peripheral surface, and further,
Since the chamfers 2 provided at predetermined intervals along the outer edge have the function of engaging with the chamfers of the hub sleeve, which is also a mating member, they are required to have strength, wear resistance, and compatibility with the mating member. , therefore, high-strength brass with these characteristics is often used in its manufacture. In addition, there is also a so-called pin type synchronizing ring, which has a thread on the outer circumferential side and rubs against a tapered cone, which is a mating member, on the outer circumferential side.

[Problem that the invention seeks to solve]

However, with the increase in the output of transmissions in recent years, the above-mentioned conventional high-strength brass synchronizing ring has been particularly affected by contact with at least one of the mating members of the above-mentioned taper cone, key, and chamfer of the hub sleeve. As the bearing surface is subjected to high surface pressure, the initial conformability decreases, which leads to frequent abnormal wear due to bright surface wear and adhesive wear, leading to a shortened service life. .

[Failure to solve the problem]

Therefore, the present inventors conducted research to solve the problems of the conventional synchronizing ring for transmissions made of high-strength brass as described above, and found that, in weight% (hereinafter, weight I% is indicated), Zn: 20-40%, /u: 2-8%, Ti and Z
Contains 1'PIi or 2 types of r: 0.1-3%, Sn: 0.1-3%, and further contains Mn: 0.1-5%, if necessary. , and the rest is made of a Cu-based alloy having a composition consisting of Cu and unavoidable impurities, and at the required places of the contact surface with the mating member, that is, the taper cone, the key, and the chamfer of the hub sleeve. Synchronous rings for transmissions made of Cu alloy have a work-hardened layer with an average layer thickness of 5 to 300 μm formed on the contact surface by shot blasting or cold pressing, and are suitable for high output of transmissions. They found that even under conditions of use under the high surface pressure associated with this, it exhibits excellent initial conformability, and the occurrence of abnormal wear in the early stages of use is suppressed.

This invention has been made based on the above knowledge, and the reason why the component composition and the average layer thickness of the work-hardened layer are limited to the above-mentioned values will be explained.

(a) zn and M These components determine the base structure of the alloy, improve the wear resistance of the base, provide the strength and toughness necessary for the synchronous ring, and further improve fatigue strength and It has excellent yield strength and is essential for forming a work-hardened layer on the ring surface that prevents adhesion (seizure) due to plastic flow caused by local high-temperature heating, thereby preventing abnormal initial wear and improving initial conformability. However, if the content is less than 20% and Al: less than 2%, not only the above properties cannot be ensured, but also it becomes difficult to form a work-hardened layer having the above properties. , while its content is Zn:
When the content exceeds 40% and Al: 8%, the toughness decreases, so the content is reduced to Zn: 20-40%.
%, Ag: 2 to 8%.

(b) Ti and Zr and 5n Ti and/or Zr and an coexist,
It has the effect of refining crystal grains and forming intermetallic compounds that are finely dispersed in the base material, improving strength and toughness, and further improving wear resistance, as well as improving the wear resistance of the work-hardened layer. However, the content is 0.1
If the content is less than 3%, the desired effect cannot be obtained, while if the content exceeds 3% each, the toughness will decrease.
r: O, 1 to 3%, Sn: 0.1 to 3%, respectively.

(c) Mn The Mn component has the effect of forming a solid solution in the base material and strengthening it, as well as making intermetallic compounds into fine spherules, thereby improving wear resistance, so it may be included as necessary. If the content is less than 0.11, the desired effect of improving the above action cannot be obtained, and on the other hand, if the content exceeds 5%, no further improvement effect will be obtained, and rather, slag will be generated during melting. Since the content increases, the content is set at 0.1 to 5%.

Incidentally, as unavoidable impurities, p+pb and even Mg may be contained, but if the total amount of these unavoidable impurities is 1% or less, it will not have any effect on the 1% property. % or less is allowed.

(d) Work-hardened layer The work-hardened layer can be formed by shot blasting, sand blasting, or topping as described above, and if it is provided only on the friction surface of the taper cone of the ring, for example, it can be formed by cold pressing using a steel die. The work-hardened layer formed in this way has excellent fatigue strength and yield strength due to its chemical composition, so it can be formed by localized high-temperature heating. As a result, seizure and other problems are suppressed, thereby preventing abnormal initial wear and exhibiting excellent initial conformability. However, if the average layer thickness is less than 5 μm, Since the desired effect could not be obtained and excellent effects could not be ensured even with an average layer thickness exceeding 300 μm, the average layer thickness was set at 5 to 300 μm.

〔Example〕

Next, the synchronization ring of the present invention will be specifically explained using examples.

Molten Cu-based alloys having the compositions shown in Table 1 were prepared using an ordinary high-frequency furnace, and then mold-casted.
Diameter = 200mmφ x length: Form a billet of 400ff, and extrude this billet into a diameter = 60uφ
After extruding it into a round bar and cutting this round bar to a specified length,
The cut pieces were hot forged at a temperature in the range of 600 to 750°C, further processed, and then mixed beads of SiC beads and steel beads with a diameter of 10 to 300 μm ( By performing shot blasting using SiC (50% by volume) and forming a work-hardened layer with the average layer thickness shown in Table 1 on the entire surface, the inner diameter: 58 mmφ x thickness: 4 Synchronous rings 1 to 14 of the present invention and comparative synchronous rings 1 to 10 having the dimensions of a parrot and having a chamfer number of 36 were manufactured, respectively.

Comparison synchronous rings 1 to 10 are those in which any of the conditions (those marked with * in Table 1) of the component composition and the average layer thickness of the work-hardened layer are outside the scope of this invention. It is.

Next, regarding the various synchronization rings obtained as a result, the rotation speed of the Cheetsk cone, which is the mating member: 1100 r
, p + m, , Pressing load: 50k19, Oil = No. 80 transmission oil, Oil temperature near 5℃, Taper cone operation 20,000 times with synchronization time of 0.3 to 0.35 seconds, synchro durability test under the following conditions. performance, depression i- (amount of wear) on the inner surface of the ring, presence or absence of adhesive wear.

The initial (up to 500 times) and late (stable period) friction coefficients were measured and observed, respectively.

Rotation speed of the tapered cone, which is the mating member: 2000r,
p, m, .

A synchro durability test was conducted under the following conditions: load: 90 kg, oil: No. 80 transmission oil, oil temperature near 0°C, taper cone operation: 5,000 times with a synchronization time of 0.25 to 0.3 seconds, and the ring The presence or absence of cracks and deformation was observed. These results are shown in Table 1.

〔Effect of the invention〕

From the results shown in Table 1, the synchronization rings 1 to 14 of the present invention
Both have high strength and toughness, and exhibit excellent conformability in the initial stage of practical use, no abnormal wear, and excellent wear resistance, even under high surface pressure conditions. As seen in Comparative Synchronization Rings 1 to 10, it is clear that if any of the constituent requirements falls outside the scope of the present invention, at least one of the above characteristics will be inferior. . It goes without saying that similar results can be obtained with a pin-type synchronous ring.

As mentioned above, the Cu-based alloy synchronizing ring for transmissions of the present invention has high strength and toughness, and is particularly good in initial conformability, making it suitable for practical use under harsh conditions associated with higher output of transmissions. Even during this process, there is no occurrence of abnormal wear such as bright surface wear or adhesive wear, and it exhibits excellent wear resistance over an extremely long period of time.

[Brief explanation of drawings]

FIG. 1 is a perspective view illustrating a synchronizing ring for a transmission. l... Tapered cone friction surface (inner surface), 2... Chamfer, 3... Keyway.

Claims (2)

[Claims] (1) Contains Zn: 20-40%, Al: 2-8%, one or two of Ti and Zr: 0.1-3%, Sn: 0.1-3%, and the rest is made of a Cu-based alloy having a composition (more than % by weight) consisting of Cu and unavoidable impurities, and a work-hardened layer of 5 to 300 μm is applied to the required locations on the contact surface with the mating member.
A synchronizing ring for a transmission made of a Cu-based alloy and formed with an average layer thickness of m. (2) Contains Zn: 20-40%, Al: 2-8%, one or two of Ti and Zr: 0.1-3%, Sn: 0.1-3%, and further , Mn: 0.1 to 5%, and the rest is Cu and unavoidable impurities. hardened layer 5~300μ
A synchronizing ring for a transmission made of a Cu-based alloy and formed with an average layer thickness of m.